Effect of High-Pressure Processing (HPP) on Phenolics of North Atlantic Sea Cucumber (Cucumaria frondosa)

Sea cucumber contains a wide range of bioactive compounds, including phenolics. This study investigated the free, esterified, and insoluble-bound phenolics of sea cucumber body wall as affected by high-pressure processing (HPP) pretreatment. Sea cucumber body wall was subjected to HPP (200, 400, and 600 MPa for 5, 10, and 15 min), followed by the extraction of phenolics. The contents of total phenolics and antioxidant activity were monitored. Compared to untreated samples, those treated with HPP exhibited significantly higher total phenolics, flavonoids, and antioxidant activities. Treatment of 600 MPa for 10 min offered the optimal results. The highest amount of phenolics was observed in the free phenolic fraction, followed by esterified and insoluble-bound phenolic fractions. Moreover, phenolic extracts showed inhibitory effects against cupric ion-induced low-density lipoprotein (LDL)-cholesterol oxidation, peroxyl and hydroxyl radical-induced DNA scission, alpha-glucosidase activity, and formation of advanced glycation end products (AGEs). Ultra-high-performance liquid chromatography equipped with a quadrupole time of fight and mass spectrometer (UHPLC-QTOF-MS/MS) identified 20 phenolic compounds, mainly phenolic acids and flavonoids, from the body wall of this species for the first time. Thus, sea cucumber may lead to the production of a multitude of value-added products.